10GBASE-T is an Ethernet standard that typically transmits information over a Category 6A (CAT6A) cabling channel at a rate of 10 Gigabits per second (10 Gb/s). A single 10GBASE-T channel typically includes four lanes each made up of a twisted differential pair of wires, and each pair operating at about 2.5 Gb/s. A single lane experiences both internal (near-end crosstalk (NEXT) and far-end crosstalk (FEXT)) and external (alien NEXT (ANEXT) and alien FEXT (AFEXT)) noise. Internal noise refers to noise whose source exists within that channel on one of the 4 internal lanes. Alien crosstalk refers to noise from an adjacent channel coupling onto one or more of the 4 lanes. Channel NEXT, FEXT, ANEXT, and AFEXT are typically measured according to ANSI/TIA-568-C.2 as attenuation to crosstalk ratio (ACR), far-end (ACR-F), power sum alien NEXT (PSANEXT), and power sum alien ACR-F (PSAACR-F), respectively. While active equipment can cancel out some amount of internal noise, it typically does not provide cancellation of alien crosstalk. Given the relative close proximity of both cables and connectors in a typical data center application, and the lack of alien crosstalk countermeasures in active equipment such as switches and servers, alien crosstalk between neighboring channels is a major concern within data centers, particularly with 10GBASE-T Ethernet. This alien crosstalk (either near-end (ANEXT), or far-end (AFEXT)) can occur between neighboring cables or between neighboring connectors (such as RJ45 jacks) of different channels. Crosstalk between the connectors may occur within high density patch panels when the connectors are in close proximity to each other. Crosstalk among cables typically occurs when cables are bundled together.
US Patent Application Publication Nos. 2010/0116521 (Nordin, et al.), 2010/0224389 (Jenner et al.), and 2010/0282493 (Nordin et al.), all incorporated by reference as if fully set forth herein, describe cables with discontinuous foil wrapped around the four twisted pairs. These foils effectively reduce alien crosstalk that would occur between cables bundled together. Additionally, US Patent Application Publication No. 2010/0197162 (Straka, et al.), incorporated by reference as if fully set forth herein, describes a jack with a discontinuous metallic foil surrounding it. This metallic foil also helps to reduce alien crosstalk between neighboring connectors, particularly within high density patch panel applications.
One primary source of alien crosstalk between neighboring connectors without a metallic foil is alien coupling among the insulation displacement contacts (IDCs). One reason coupling can exist in this region is that the IDCs are relatively large metallic structures designed to easily facilitate termination of the wires of a cable. As relatively large metallic structures, IDCs can capacitively and inductively couple to each other, either within a jack (resulting in NEXT or FEXT) or to neighboring jacks, which may result in increased alien crosstalk. Therefore, there exists a need for a communication connector that allows for relative ease of termination to a communication cable, with reduced crosstalk, including alien crosstalk, between neighboring channels.